A special roughened morphology electrolytic copper foil and a method for preparing the same

Abstract

The present application relates to a kind of special roughening morphology electrolytic copper foil and its preparation method, and the special roughening morphology is specifically the roughening organization of treatment surface is sheet morphology and globular morphology.The present application forms the fine copper tumor of special sheet morphology and globular morphology on the rough surface of copper foil, and copper tumor particle covers entire rough surface peak and valley, on the one hand, roughness is reduced while, the pressing area of copper foil surface and resin is increased;On the other hand, the copper tumor structure of staggered distribution, there are more pores, in the process of pressing plate, resin can be embedded into pore to ensure that copper foil is enough peel strength.

Description

Technical Field

[0001] This invention belongs to the field of copper foil, and specifically relates to an electrolytic copper foil with a special roughened morphology and its preparation method. Background Technology

[0002] In recent years, the trend towards thinner and lighter PCBs and the low transmission loss characteristics of high-frequency, high-speed circuits have made the surface morphology or roughness of conductors increasingly important at higher frequencies. This requires copper foil to achieve sufficient peel strength while maintaining low roughness. Roughness and peel strength are mutually restrictive, increasing the production difficulty of high-frequency, high-speed copper foil and imposing more stringent performance requirements. Therefore, simultaneously achieving low roughness and sufficient peel strength has become crucial for copper foil manufacturing technology.

[0003] The side of the raw foil that contacts the cathode roller is called the smooth surface or S-side, and the other side is called the rough surface or M-side. The smooth surface is mirror-image of the cathode roller surface, with a smooth surface and low roughness, while the rough surface has an undulating, mountain-like microstructure and higher roughness. Surface treatment of the raw foil involves electroplating to roughen the treated surface, which is essentially a process of metal electrocrystallization. Simultaneously, crystal nuclei are generated and grown. The speed of these two processes determines the coarseness of the copper nodules. When the crystal nucleus generation rate is greater than the crystal nucleus growth rate, a fine, tightly packed roughened layer is obtained; conversely, the roughened layer has a coarse crystal structure. During the surface treatment of the rough surface of the copper foil, the mountain-like structure of the rough surface creates a tip discharge effect. The roughened copper nodules concentrate at the top of the peaks, resulting in protrusions and unevenness in the roughened layer, leading to higher roughness in the finished foil and affecting signal transmission and insulation safety. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a special roughened morphology electrolytic copper foil and its preparation method. By forming fine copper nodules with special sheet-like and spherical morphologies on the rough surface of the copper foil, and the copper nodule particles covering the peaks and valleys of the rough surface, on the one hand, the roughness is reduced and the bonding area between the copper foil surface and the resin is increased; on the other hand, the staggered copper nodule structure has more pores, and during the pressing process, the resin can be embedded into the pores to ensure sufficient peel strength of the copper foil.

[0005] The present invention provides an electrolytic copper foil with a special roughened morphology, wherein the special roughened morphology specifically refers to the roughened structure of the treated surface exhibiting a lamellar or spherical morphology.

[0006] The lamellar coarsening structure has a length between 500 and 1200 nm and a thickness between 60 and 100 nm, with a length-to-thickness ratio of 7 to 20. The spherical coarsening structure has a diameter between 200 and 600 nm. The ratio of lamellar to spherical coarsening structures is between 1:1 and 5:1. The coarsening structure uniformly covers the peaks and valleys of the entire rough surface, resulting in strong deep plating capability.

[0007] When performing microscopic parameter analysis using a laser confocal microscope, the measured surface roughness Rz was between 8.0 and 10.0 μm, the root mean square roughness Rq was between 1.40 and 2.00 μm, the surface roughness Sz was between 12 and 17 μm, and the peak density Spd was between 9000 and 13000 mm². -2 The peak curvature Spc is between 300 and 500 mm. -1 Between these values, the interface expansion area ratio Sdr is between 40% and 100%.

[0008] The peel strength between the copper foil of the present invention and the IT968G type PPO resin substrate is not less than 1.30 kgf / cm.

[0009] The copper foil of the present invention and the PCB made by IT968G semi-curing process have an insertion loss between -1.10 and 2.00 dB / inchch at a signal frequency f = 4 GHz.

[0010] This invention also provides a method for preparing electrolytic copper foil with a special roughened morphology, comprising the following steps:

[0011] (1) The copper foil rough surface is pretreated by electrochemical polishing using a pulse power supply to remove the oxide layer and oil stains on the copper foil surface;

[0012] (2) An additive-assisted roughening treatment technique is used to form a roughened layer on the rough surface of the copper foil. The roughened surface of the copper foil after the above pretreatment is subjected to multiple roughening and curing treatments in a roughening solution containing additives using a DC power supply. The roughening current density is 8-13 A / dm. 2 The curing current density is between 10 and 15 A / dm². 2 The solid-to-coarse ratio is between 1.0 and 1.3, and the roughening and curing time is between 5 and 10 seconds.

[0013] (3) After the roughening treatment is completed, the copper foil is then passivated with a metal barrier layer and coated with silane on both sides; finally, it is dried with hot air to prepare the finished copper foil.

[0014] The process parameters for the electrochemical polishing pretreatment in step (1) are: pulse frequency between 500-1800Hz, and average current density between 3-6A / dm². 2The duty cycle is between 20-50%, and the processing time is between 5-10 seconds.

[0015] The additives in step (2) are two or more of the following: benzylated polyethyleneimine, titanium sulfite, diaminourea polymer, polyethylene glycol, sodium dimethylformamide sulfonate, and chloral hydrate. The concentration of each additive is between 0.0005 and 0.01 wt%, and the percentage is based on the total mass of the roughening liquid.

[0016] The process parameters for the roughening treatment in step (2) are: current density between 9 and 19 A / dm. 2 The electroplating time is between 5 and 10 seconds; the curing process parameters are: current density between 10 and 20 A / dm³. 2 The electroplating time is between 5 and 10 seconds. The curing process involves immersing the roughened copper foil surface in a curing solution and electroplating it using a DC power supply to form a cured copper layer on the roughened copper layer, thereby enhancing the bonding stability between the roughened particles and the copper foil substrate.

[0017] The passivation process parameters in step (3) are: current density between 0.5 and 0.8 A / dm³. 2 The electroplating time is between 10 and 20 seconds. After roughing and curing, the copper foil is placed in a passivation solution, and nickel, zinc, and chromium are plated on both sides of the copper foil respectively. A metal barrier layer is formed on the treated surface of the copper foil, which improves the oxidation resistance of the copper foil at room temperature and high temperature.

[0018] The silane coating in step (3) involves coating the treated surface of the copper foil with a silane coupling agent to provide chemical bonding with the resin.

[0019] The entire electroplating process employs direct current electrodeposition technology, and the roughening electroplating solution consists of: Cu 2+ The concentration of the plating solution is between 9 and 13 g / L, the concentration of H2SO4 is between 90 and 130 g / L, and the temperature of the roughening plating solution is between 30 ± 3℃; the composition of the curing plating solution is: Cu 2+ The concentration of the curing electroplating solution is between 40 and 70 g / L, the concentration of H2SO4 is between 80 and 140 g / L, and the temperature of the curing electroplating solution is between 50 ± 5℃; the composition of the passivation electroplating solution is: Ni ion concentration between 0.8 and 1.2 g / L, Zn ion concentration between 0.7 and 1.1 g / L, Cr ion concentration between 0.9 and 1.3 g / L, K2P4O7 concentration between 30 and 60 g / L, and the temperature of the passivation electroplating solution is between 40 ± 3℃.

[0020] Beneficial effects

[0021] This invention forms fine copper nodules with special sheet-like and spherical morphologies on the rough surface of copper foil, with the nodule particles covering the entire surface's peaks and valleys. This reduces roughness while increasing the bonding area between the copper foil and resin. Furthermore, the interwoven nodule structure contains numerous pores, allowing resin to embed into these pores during the pressing process, ensuring sufficient peel strength for the copper foil. This invention's specially shaped copper nodule roughening structure reduces copper foil surface roughness while maintaining sufficient peel strength, resulting in low signal transmission loss and suitability for high-frequency, high-speed circuit fabrication. Attached Figure Description

[0022] Figure 1 The SEM morphology of the treated surface of the 35μm finished copper foil after surface treatment in Comparative Example 1 is shown.

[0023] Figure 2 The image shows the SEM morphology of the treated surface of the 35μm finished copper foil after surface treatment in Example 1.

[0024] Figure 3 The image shows the SEM cross-sectional morphology of a 35μm finished copper foil after surface treatment in Example 1.

[0025] Figure 4 The SEM morphology of the roughened structure of the finished copper foil with a diameter of 35 μm after surface treatment in Example 1;

[0026] Figure 5 Laser confocal contour plot of the surface roughness of the finished copper foil surface in Comparative Example 1;

[0027] Figure 6 Laser confocal contour plot of surface roughness of the finished copper foil surface in Example 1;

[0028] Figure 7 This is a schematic diagram of a coarsened tissue structure with a conventional spherical morphology.

[0029] Figure 8 This is a schematic diagram of the special morphological coarsening tissue structure of the present invention. Detailed Implementation

[0030] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0031] The surface treatment of the electrolytic copper foil in this embodiment adopts a three-step roughing and three-step solidification process (three-step roughing and solidification) + passivation (nickel, zinc, and chromium plating for anti-oxidation treatment). The basic process is as follows: raw foil → pretreatment → roughing → solidification → roughing → solidification → roughing → solidification → passivation → silane coupling agent → water washing → drying → finished copper foil. The entire electroplating process adopts a direct current electrodeposition process. The composition of the roughening electroplating solution is: Cu 2+ The concentration of the plating solution was 11 g / L, the concentration of H2SO4 was 110 g / L, and the temperature of the roughening plating solution was 30℃; the composition of the curing plating solution was: Cu 2+ The concentration of the curing electroplating solution is 55 g / L, the concentration of H2SO4 is 90 g / L, and the temperature of the curing electroplating solution is 50℃; the composition of the passivation electroplating solution is: Ni ion concentration 1.0 g / L, Zn ion concentration 0.9 g / L, Cr ion concentration 1.1 g / L, K2P4O7 concentration 45 g / L, and the temperature of the passivation electroplating solution is 40℃. The specific steps are as follows:

[0032] 1) Electrochemical polishing pretreatment was performed on the rough surface of 35μm electrolytic green foil using a pulsed power supply to remove the oxide layer and oil stains. The pretreatment solution was a mixed solution of H2SO4 (70g / L) and H2O2 (30wt%), with a pulse frequency of 1200Hz and a current density of 5A / dm³. 2 The duty cycle is 30%, and the preprocessing time is controlled at around 7 seconds.

[0033] 2) The pretreated green foil undergoes a series of processes: roughening, curing, roughening, curing, roughening, and curing. The roughening current density is 14 A / dm³. 2 The total curing current density is 15 A / dm³. 2 The solid-to-roughness ratio is 1.20, and the electroplating time for each roughening and curing process is 7 seconds.

[0034] 3) After three roughing and three solidification processes, the copper foil is washed with water and then subjected to a metal barrier passivation treatment. The copper foil is placed in a passivation solution, and nickel, zinc, and chromium are plated on both sides of the copper foil respectively. A metal barrier layer is formed on the treated surface of the copper foil, which improves the oxidation resistance of the copper foil at both room temperature and high temperature. The current density is 0.70 A / dm³. 2 The electroplating time is 15 seconds;

[0035] 4) After passivation treatment, both sides of the copper foil are washed with water. Then, a silane coupling agent is coated on the treated side of the copper foil. Finally, the surface of the copper foil is dried with hot air to obtain a surface-treated electrolytic copper foil.

[0036] Comparative Example 1

[0037] The rough surface of a 35μm electrolytic copper foil was pre-treated with electrochemical polishing for 7 seconds to remove the surface oxide layer. Then, a three-step roughing and curing process was performed. Benzyl polyethyleneimine (0.0015 wt%) was added to the roughing solution. After each roughing or curing step, the copper foil was washed with water before proceeding to the next step. After the three-step roughing and curing process, passivation plating with nickel, zinc, and chromium layers was performed to improve oxidation resistance at both room temperature and high temperature. After passivation, the foil was washed with water, coated with a silane coupling agent, and then hot-air dried to obtain the finished 35μm copper foil.

[0038] The physical properties of the 35μm finished copper foil after processing with the comparative parameters are as follows: contact roughness Rz is 8.35μm, non-contact roughness Rz is 12.77μm, root mean square roughness Rq is 2.38μm, surface roughness Sz is 20.86μm, interface expansion area ratio Sdr is 122.40%, and peak curvature Spc is 664.12mm. -1 The peak density Spd is 15000 mm. -2 The peel strength between the 35μm finished foil produced using these comparative parameters and the IT968G type PPO resin substrate is 1.31 kgf / cm. The PCB board manufactured by laminating the 35μm finished copper foil produced using these comparative parameters and the PPO resin substrate has an insertion loss of -2.97 dB / inch at a frequency of 4 GHz.

[0039] Example 1

[0040] 35μm electrolytic copper foil underwent a 7-second acid pickling pretreatment to remove the surface oxide layer. Following this, a three-step roughing and curing process was performed. A composite additive (benzyl polyethyleneimine + titanium sulfite) was added to the roughing solution, with the concentrations of benzyl polyethyleneimine (0.0005 wt%) and titanium sulfite (0.0003 wt%). After each roughing or curing step, the copper foil was washed with water before proceeding to the next step. After the three-step roughing and curing process, passivation plating with nickel, zinc, and chromium layers was performed to improve oxidation resistance at both room temperature and high temperature. After passivation, the foil was washed with water, coated with a silane coupling agent, and then hot-air dried to obtain the finished 35μm copper foil.

[0041] The physical properties of the 35μm finished copper foil after parameter processing according to this embodiment are as follows: contact roughness Rz is 6.91μm, non-contact roughness Rz is 9.38μm, root mean square roughness Rq is 1.91μm, surface roughness Sz is 16.80μm, interface expansion area ratio Sdr is 95.23%, and peak curvature Spc is 470.15mm. -1 The peak density Spd is 11600 mm. -2The peel strength of the 35μm finished copper foil produced according to the parameters of this embodiment after lamination with an IT968G type PPO resin substrate is 1.35 kgf / cm. The insertion loss of the PCB board processed by laminating the 35μm finished copper foil produced according to the parameters of this embodiment with an IT968G type PPO resin substrate is -1.98 dB / inch when tested at a frequency of 4 GHz.

[0042] Example 2

[0043] 35μm electrolytic copper foil underwent a 7-second acid pickling pretreatment to remove the surface oxide layer. Following this, a three-step roughing and curing process was performed. A composite additive (benzyl polyethyleneimine + titanium sulfite) was added to the roughing solution, with the concentrations of benzyl polyethyleneimine (0.001 wt%) and titanium sulfite (0.0005 wt%). After each roughing or curing step, the copper foil was washed with water before proceeding to the next step. After the three-step roughing and curing process, passivation plating with nickel, zinc, and chromium layers was performed to improve oxidation resistance at both room temperature and high temperature. After passivation, the foil was washed with water, coated with a silane coupling agent, and then hot-air dried to obtain the finished 35μm copper foil.

[0044] The physical properties of the 35μm finished copper foil after parameter processing according to this embodiment are as follows: contact roughness Rz is 6.73μm, non-contact roughness Rz is 8.63μm, root mean square roughness Rq is 1.57μm, surface roughness Sz is 15.60μm, interface expansion area ratio Sdr is 71.99%, and peak curvature Spc is 397.48mm. -1 Peak density Spd is 10000 mm. -2 The peel strength of the 35μm finished copper foil produced according to the parameters of this embodiment after lamination with an IT968G type PPO resin substrate is 1.41 kgf / cm. The insertion loss of the PCB board processed by laminating the 35μm finished copper foil produced according to the parameters of this embodiment with an IT968G type PPO resin substrate is -1.66 dB / inch when tested at a frequency of 4 GHz.

[0045] Example 3

[0046] 35μm electrolytic copper foil underwent a 7-second acid pickling pretreatment to remove the surface oxide layer. Following this, a three-step roughing and curing process was performed. A composite additive (benzyl polyethyleneimine + titanium sulfite) was added to the roughing solution, with the concentrations of benzyl polyethyleneimine (0.003 wt%) and titanium sulfite (0.001 wt%). After each roughing or curing step, the copper foil was washed with water before proceeding to the next step. After the three-step roughing and curing process, passivation plating with nickel, zinc, and chromium layers was performed to improve oxidation resistance at both room temperature and high temperature. After passivation, the foil was washed with water, coated with a silane coupling agent, and then hot-air dried to obtain the finished 35μm copper foil.

[0047] The physical properties of the 35μm finished copper foil after parameter processing according to this embodiment are as follows: contact roughness Rz is 6.38μm, non-contact roughness Rz is 8.38μm, root mean square roughness Rq is 1.47μm, surface roughness Sz is 13.12μm, interface expansion area ratio Sdr is 56.57%, and peak curvature Spc is 303.40mm. -1 The peak density Spd is 10700 mm. -2 The peel strength of the 35μm finished copper foil produced according to the parameters of this embodiment after laminating it with an IT968G type PPO resin substrate is 1.37 kgf / cm. The insertion loss of the PCB board processed by laminating the 35μm finished copper foil produced according to the parameters of this embodiment with an IT968G type PPO resin substrate is -1.23 dB / inch when tested at a frequency of 4 GHz.

[0048] Example 4

[0049] 35μm electrolytic copper foil underwent a 7s acid pickling pretreatment to remove the surface oxide layer. Following this, a three-step roughing and curing process was performed. A composite additive (benzyl polyethyleneimine + titanium sulfite) was added to the roughing solution, with the concentrations of benzyl polyethyleneimine (0.005wt%) and titanium sulfite (0.002wt%). After each roughing or curing step, the copper foil was washed with water before proceeding to the next step. After the three-step roughing and curing process, passivation plating with nickel, zinc, and chromium layers was performed to improve oxidation resistance at both room temperature and high temperature. After passivation, the foil was washed with water, coated with a silane coupling agent, and then hot-air dried to obtain the finished 35μm copper foil.

[0050] The physical properties of the 35μm finished copper foil after parameter processing according to this embodiment are as follows: contact roughness Rz is 6.23μm, non-contact roughness Rz is 8.10μm, root mean square roughness Rq is 1.41μm, surface roughness Sz is 12.98μm, interface expansion area ratio Sdr is 52.62%, and peak curvature Spc is 297.71mm. -1The peak density Spd is 10200 mm. -2 The peel strength of the 35μm finished copper foil produced according to the parameters of this embodiment after lamination with an IT968G type PPO resin substrate is 1.33 kgf / cm. The insertion loss of the PCB board processed by laminating the 35μm finished copper foil produced according to the parameters of this embodiment with an IT968G type PPO resin substrate is -1.15 dB / inch when tested at a frequency of 4 GHz.

[0051] Example 5

[0052] 35μm electrolytic copper foil was pre-treated with acid pickling for 7 seconds to remove the surface oxide layer. Then, it underwent a three-step roughing and curing process. A composite additive (benzyl polyethyleneimine + titanium sulfite + diaminourea polymer) was added to the roughing solution. The concentrations of benzyl polyethyleneimine, titanium sulfite, and diaminourea polymer in the roughing solution were 0.001wt%, 0.0005wt%, and 0.0005wt%, respectively. After each roughing or curing step, the copper foil was washed with water before proceeding to the next step. After the three-step roughing and curing process, passivation plating with nickel, zinc, and chromium layers was performed to improve oxidation resistance at both room temperature and high temperature. After passivation, the foil was washed with water, coated with a silane coupling agent, and then hot-air dried to obtain the finished 35μm copper foil.

[0053] The physical properties of the 35μm finished copper foil after parameter processing according to this embodiment are as follows: contact roughness Rz is 6.52μm, non-contact roughness Rz is 8.23μm, root mean square roughness Rq is 1.50μm, surface roughness Sz is 15.11μm, interface expansion area ratio Sdr is 68.32%, and peak curvature Spc is 382.13mm. -1 The peak density Spd is 10500 mm. -2 The peel strength of the 35μm finished copper foil produced according to the parameters of this embodiment after laminating it with an IT968G type PPO resin substrate is 1.40 kgf / cm. The insertion loss of the PCB board processed by laminating the 35μm finished copper foil produced according to the parameters of this embodiment with an IT968G type PPO resin substrate is -1.59 dB / inch when tested at a frequency of 4 GHz.

[0054] Example 6

[0055] 35μm electrolytic copper foil was pre-treated with acid pickling for 7 seconds to remove the surface oxide layer. Then, it underwent a three-step roughing and curing process. A composite additive (benzyl polyethyleneimine + titanium sulfite + diaminourea polymer) was added to the roughing solution. The concentrations of benzyl polyethyleneimine, titanium sulfite, and diaminourea polymer in the roughing solution were 0.003wt%, 0.001wt%, and 0.001wt%, respectively. After each roughing or curing step, the copper foil was washed with water before proceeding to the next step. After the three-step roughing and curing process, passivation plating with nickel, zinc, and chromium layers was performed to improve oxidation resistance at both room temperature and high temperature. After passivation, the foil was washed with water, coated with a silane coupling agent, and then hot-air dried to obtain the finished 35μm copper foil.

[0056] The physical properties of the 35μm finished copper foil after parameter processing according to this embodiment are as follows: contact roughness Rz is 6.29μm, non-contact roughness Rz is 8.41μm, root mean square roughness Rq is 1.45μm, surface roughness Sz is 12.85μm, interface expansion area ratio Sdr is 60.89%, and peak curvature Spc is 294.65mm. -1 The peak density Spd is 10100 mm. -2 The peel strength of the 35μm finished copper foil produced according to the parameters of this embodiment after lamination with an IT968G type PPO resin substrate is 1.35 kgf / cm. The insertion loss of the PCB board processed by laminating the 35μm finished copper foil produced according to the parameters of this embodiment with an IT968G type PPO resin substrate is -1.19 dB / inch when tested at a frequency of 4 GHz.

[0057] The performance of the finished copper foils prepared by the surface treatment of the above embodiments and comparative examples was tested, and the results are shown in Table 1.

[0058] Table 1. Performance Comparison of Copper Foil Prepared in Examples and Comparative Examples

[0059]

[0060] contrast Figure 1 and Figure 2 In Comparative Example 1, the copper foil treatment resulted in a severe tip discharge effect, with a large number of copper particles deposited at the peaks of the copper foil surface profile, exhibiting a cauliflower-like morphology. The number of copper nodules at the waist and bottom of the peaks was very small, resulting in poor deep plating, high roughness, and easy shedding of copper powder, leading to low peel strength. In contrast, the peak and valley surfaces of the copper foil in Example 1 were uniformly covered by a coarsened structure, the growth of copper nodules at the peaks was inhibited, and the coarsened structure was distributed in an interwoven pattern of fine lamellar structures (see...). Figure 3 , 4 This demonstrates a superior deep-plating effect, with low roughness and no reduction in peel strength. (Comparison) Figure 5 and Figure 6 This allows for a more direct comparison between Example 1 and Comparative Example 1, showing that the copper foil treated surface has a lower undulation profile. Schematic diagrams of the conventional spherical and special morphological coarsened microstructures are shown below. Figure 7 , 8 As shown, this special morphological coarsening structure, compared with the conventional spherical morphological coarsening structure, has a larger specific surface area and smaller pores. During the bonding process with resin, the larger surface area is beneficial for the silane coupling agent to function, while the smaller pores are beneficial for the resin to provide sufficient peel strength after curing. Regarding the copper foil properties (see Table 1), compared with Comparative Example 1, Examples 1, 2, 3, 4, 5, and 6 all have lower roughness Rz and Sz, without a decrease in peel strength, and also have lower insertion loss.

[0061] Finally, it should be emphasized that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A special type of coarsened electrolytic copper foil, characterized in that: The specific coarsening morphology refers to the coarsening structure of the treated surface exhibiting both lamellar and spherical morphologies; the length of the lamellar coarsening structure is between 500 and 1200 nm, the thickness is between 60 and 100 nm, and the length-to-thickness ratio is between 7 and 20; the diameter of the spherical coarsening structure is between 200 and 600 nm; and the ratio of the number of lamellar coarsening structures to the number of spherical coarsening structures is between 1:1 and 5:

1.

2. A method for preparing the special roughened morphology electrolytic copper foil as described in claim 1, comprising the following steps: (1) The copper foil rough surface is pretreated by electrochemical polishing using a pulse power supply to remove the oxide layer and oil stains on the copper foil surface; (2) An additive-assisted roughening treatment technique is used to form a roughened layer on the rough surface of the copper foil. The roughened surface of the copper foil after the above pretreatment is subjected to multiple roughening and curing treatments in a roughening solution containing additives using a DC power supply. The roughening current density is 8~13 A / dm. 2 The curing current density is between 10 and 15 A / dm³. 2 The solid-to-coarse ratio is between 1.0 and 1.3, and the roughening and curing time is between 5 and 10 seconds. (3) After the roughening treatment is completed, the copper foil is then passivated with a metal barrier layer and coated with silane on both sides; finally, it is dried with hot air to prepare the finished copper foil.

3. The preparation method according to claim 2, characterized in that: The process parameters for the electrochemical polishing pretreatment in step (1) are: pulse frequency between 500-1800 Hz, and average current density between 3-6 A / dm³. 2 The duty cycle is between 20-50%, and the processing time is between 5-10 seconds.

4. The preparation method according to claim 2, characterized in that: The additives in step (2) are two or more of the following: benzylated polyethyleneimine, titanium sulfite, diaminourea polymer, polyethylene glycol, sodium dimethylformamide sulfonate, and chloral hydrate, with the concentration of each additive between 0.0005 and 0.01 wt%.

5. The preparation method according to claim 2, characterized in that: The passivation process parameters in step (3) are: current density between 0.5 and 0.8 A / dm³. 2 The electroplating time is between 10 and 20 seconds.

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